My 770 gtx only gets to like 80% gpu usage in crysis 3 and just sits there idle on 60+ fps on highest settings

If your fps is 60+ and your refresh rate is 60 then there is no use of 100% gpu usage. An overclocked FX6300 will not bottleneck those cards and they aren't crap! Give me the name on an intel chip at that price which can beat the FX6300 in overall tasks?
Nothing is overkill. Now games make use of all the resources you can throw at it!